If your media is still being processed, then you should expect to see the generic placeholders until it's all done. That's the way it's supposed to work. TreeSync is also designed to resume any incomplete media transfers. This means that you don't have to leave your computer running overnight or worry what might happen if your connection is interrupted. FTM, each time you run it, will keep working on the media transfers until it's all complete. What you're experiencing is supposed to happen. Only after it's all done should you check your media (on both sides) to make sure that it all transferred correctly, as there are usually a few errors, especially if you have a lot of media items.